alts: add gRPC TSI frame protector

source/extensions/transport_sockets/alts/BUILD

@@ -24,6 +24,21 @@ envoy_cc_library(
     ],
 )
 
+envoy_cc_library(
+    name = "tsi_frame_protector",
+    srcs = [
+        "tsi_frame_protector.cc",
+    ],
+    hdrs = [
+        "tsi_frame_protector.h",
+    ],
+    repository = "@envoy",
+    deps = [
+        ":grpc_tsi_wrapper",
+        "//source/common/buffer:buffer_lib",
+    ],
+)
+
 envoy_cc_library(
     name = "tsi_handshaker",
     srcs = [

source/extensions/transport_sockets/alts/tsi_frame_protector.cc

@@ -0,0 +1,78 @@
+#include "extensions/transport_sockets/alts/tsi_frame_protector.h"
+
+#include "common/common/assert.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace TransportSockets {
+namespace Alts {
+
+// TODO(lizan): tune size later
+static constexpr uint32_t BUFFER_SIZE = 16384;
+
+TsiFrameProtector::TsiFrameProtector(CFrameProtectorPtr&& frame_protector)
+    : frame_protector_(std::move(frame_protector)) {}
+
+tsi_result TsiFrameProtector::protect(Buffer::Instance& input, Buffer::Instance& output) {
+  ASSERT(frame_protector_);
+
+  unsigned char protected_buffer[BUFFER_SIZE];
+  while (input.length() > 0) {
+    auto* message_bytes = reinterpret_cast<unsigned char*>(input.linearize(input.length()));
+    size_t protected_buffer_size = BUFFER_SIZE;
+    size_t processed_message_size = input.length();
+    tsi_result result =
+        tsi_frame_protector_protect(frame_protector_.get(), message_bytes, &processed_message_size,
+                                    protected_buffer, &protected_buffer_size);
+    if (result != TSI_OK) {
+      ASSERT(result != TSI_INVALID_ARGUMENT && result != TSI_UNIMPLEMENTED);
+      return result;
+    }
+    output.add(protected_buffer, protected_buffer_size);
+    input.drain(processed_message_size);
+  }
+
+  // TSI may buffer some of the input in its internal, flushing its buffer to protected_buffer to
+  // avoid some of input is not written to socket.
+  size_t still_pending_size;
+  do {
+    size_t protected_buffer_size = BUFFER_SIZE;
+    tsi_result result = tsi_frame_protector_protect_flush(
+        frame_protector_.get(), protected_buffer, &protected_buffer_size, &still_pending_size);
+    if (result != TSI_OK) {
+      ASSERT(result != TSI_INVALID_ARGUMENT && result != TSI_UNIMPLEMENTED);
+      return result;
+    }
+    output.add(protected_buffer, protected_buffer_size);
+  } while (still_pending_size > 0);
+
+  return TSI_OK;
+}
+
+tsi_result TsiFrameProtector::unprotect(Buffer::Instance& input, Buffer::Instance& output) {
+  ASSERT(frame_protector_);
+
+  unsigned char unprotected_buffer[BUFFER_SIZE];
+
+  while (input.length() > 0) {
+    auto* message_bytes = reinterpret_cast<unsigned char*>(input.linearize(input.length()));
+    size_t unprotected_buffer_size = BUFFER_SIZE;
+    size_t processed_message_size = input.length();
+    tsi_result result = tsi_frame_protector_unprotect(frame_protector_.get(), message_bytes,
+                                                      &processed_message_size, unprotected_buffer,
+                                                      &unprotected_buffer_size);
+    if (result != TSI_OK) {
+      ASSERT(result != TSI_INVALID_ARGUMENT && result != TSI_UNIMPLEMENTED);
+      return result;
+    }
+    output.add(unprotected_buffer, unprotected_buffer_size);
+    input.drain(processed_message_size);
+  }
+
+  return TSI_OK;
+}
+
+} // namespace Alts
+} // namespace TransportSockets
+} // namespace Extensions
+} // namespace Envoy

source/extensions/transport_sockets/alts/tsi_frame_protector.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include "envoy/buffer/buffer.h"
+
+#include "extensions/transport_sockets/alts/grpc_tsi.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace TransportSockets {
+namespace Alts {
+
+/**
+ * A C++ wrapper for tsi_frame_protector interface.
+ * For detail of tsi_frame_protector, see
+ * https://github.com/grpc/grpc/blob/v1.10.0/src/core/tsi/transport_security_interface.h#L70
+ *
+ * TODO(lizan): migrate to tsi_zero_copy_grpc_protector for further optimization
+ */
+class TsiFrameProtector final {
+public:
+  explicit TsiFrameProtector(CFrameProtectorPtr&& frame_protector);
+
+  /**
+   * Wrapper for tsi_frame_protector_protect
+   * @param input supplies the input buffer, the method will drain it when it is processed.
+   * @param output supplies the output buffer
+   * @return tsi_result the status.
+   */
+  tsi_result protect(Buffer::Instance& input, Buffer::Instance& output);
+
+  /**
+   * Wrapper for tsi_frame_protector_unprotect
+   * @param input supplies the input buffer, the method will drain it when it is processed.
+   * @param output supplies the output buffer
+   * @return tsi_result the status.
+   */
+  tsi_result unprotect(Buffer::Instance& input, Buffer::Instance& output);
+
+private:
+  CFrameProtectorPtr frame_protector_;
+};
+
+typedef std::unique_ptr<TsiFrameProtector> TsiFrameProtectorPtr;
+
+} // namespace Alts
+} // namespace TransportSockets
+} // namespace Extensions
+} // namespace Envoy

test/extensions/transport_sockets/alts/BUILD

@@ -11,6 +11,16 @@ load(
 
 envoy_package()
 
+envoy_extension_cc_test(
+    name = "tsi_frame_protector_test",
+    srcs = ["tsi_frame_protector_test.cc"],
+    extension_name = "envoy.transport_sockets.alts",
+    deps = [
+        "//source/extensions/transport_sockets/alts:tsi_frame_protector",
+        "//test/mocks/buffer:buffer_mocks",
+    ],
+)
+
 envoy_extension_cc_test(
     name = "tsi_handshaker_test",
     srcs = ["tsi_handshaker_test.cc"],

test/extensions/transport_sockets/alts/tsi_frame_protector_test.cc

@@ -0,0 +1,103 @@
+#include "common/buffer/buffer_impl.h"
+
+#include "extensions/transport_sockets/alts/tsi_frame_protector.h"
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "src/core/tsi/fake_transport_security.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace TransportSockets {
+namespace Alts {
+
+using testing::InSequence;
+using testing::Invoke;
+using testing::NiceMock;
+using testing::SaveArg;
+using testing::Test;
+using testing::_;
+using namespace std::string_literals;
+
+/**
+ * Test with fake frame protector. The protected frame header is 4 byte length (little endian,
+ * include header itself) and following the body.
+ */
+class TsiFrameProtectorTest : public Test {
+public:
+  TsiFrameProtectorTest()
+      : frame_protector_(CFrameProtectorPtr{tsi_create_fake_frame_protector(nullptr)}) {}
+
+protected:
+  TsiFrameProtector frame_protector_;
+};
+
+TEST_F(TsiFrameProtectorTest, Protect) {
+  {
+    Buffer::OwnedImpl input, encrypted;
+    input.add("foo");
+
+    EXPECT_EQ(TSI_OK, frame_protector_.protect(input, encrypted));
+    EXPECT_EQ("\x07\0\0\0foo"s, encrypted.toString());
+  }
+
+  {
+    Buffer::OwnedImpl input, encrypted;
+    input.add("foo");
+
+    EXPECT_EQ(TSI_OK, frame_protector_.protect(input, encrypted));
+    EXPECT_EQ("\x07\0\0\0foo"s, encrypted.toString());
+
+    input.add("bar");
+    EXPECT_EQ(TSI_OK, frame_protector_.protect(input, encrypted));
+    EXPECT_EQ("\x07\0\0\0foo\x07\0\0\0bar"s, encrypted.toString());
+  }
+
+  {
+    Buffer::OwnedImpl input, encrypted;
+    input.add(std::string(20000, 'a'));
+
+    EXPECT_EQ(TSI_OK, frame_protector_.protect(input, encrypted));
+
+    // fake frameprotector will split long buffer to 2 "encrypted" frames with length 16K.
+    std::string expected =
+        "\0\x40\0\0"s + std::string(16380, 'a') + "\x28\x0e\0\0"s + std::string(3620, 'a');
+    EXPECT_EQ(expected, encrypted.toString());
+  }
+}
+
+TEST_F(TsiFrameProtectorTest, Unprotect) {
+  {
+    Buffer::OwnedImpl input, decrypted;
+    input.add("\x07\0\0\0bar"s);
+
+    EXPECT_EQ(TSI_OK, frame_protector_.unprotect(input, decrypted));
+    EXPECT_EQ("bar", decrypted.toString());
+  }
+
+  {
+    Buffer::OwnedImpl input, decrypted;
+    input.add("\x0a\0\0\0foo"s);
+
+    EXPECT_EQ(TSI_OK, frame_protector_.unprotect(input, decrypted));
+    EXPECT_EQ("", decrypted.toString());
+
+    input.add("bar");
+    EXPECT_EQ(TSI_OK, frame_protector_.unprotect(input, decrypted));
+    EXPECT_EQ("foobar", decrypted.toString());
+  }
+
+  {
+    Buffer::OwnedImpl input, decrypted;
+    input.add("\0\x40\0\0"s + std::string(16380, 'a'));
+    input.add("\x28\x0e\0\0"s + std::string(3620, 'a'));
+
+    EXPECT_EQ(TSI_OK, frame_protector_.unprotect(input, decrypted));
+    EXPECT_EQ(std::string(20000, 'a'), decrypted.toString());
+  }
+}
+
+} // namespace Alts
+} // namespace TransportSockets
+} // namespace Extensions
+} // namespace Envoy